Prior art patent document published US 2005/0092411 A1 discloses a tire with a central auxiliary chamber formed in the tread portion. This chamber can be inflated independently of the main chamber defined by the side walls and the tread portion. The central area of the outer surface of the tread portion, corresponding to the auxiliary chamber comprises studs. When the auxiliary chamber is not inflated, the central area of the outer surface of the tread portion forms a deepening so that the studs are retracted and do not contact the road or ground. When the auxiliary chamber is inflated, the central area of the outer surface is raised so that the studs extends beyond the general plane of the outer surface. The inflation and deflation of the auxiliary chamber is achieved by a unit comprising a pump and a valve, said unit being attached to the inner side of one of the sidewalls and pneumatically connected to the auxiliary chamber via a conduit extending along the inner face of the sidewall and the tread portion. This tire permits to provide increased traction in severe conditions such as on snow and ice, while permitting driving under normal conditions without damaging the road and without producing unnecessary additional noise. The scope of use of this tire is however quite limited since it is specifically intended for regions where ice or at least severe conditions prevail.
Prior art patent document published U.S. Pat. No. 8,020,596 B1 discloses an integrated wheel for electric vehicles which is intended to substantially reduce energy loss due to tire flex. The wheel comprises a tire made of a central outer ring and side walls made of several lateral rings, said central and lateral rings forming a general V-shaped cross-section. When the road conditions are good, the sidewalls do not substantially deform so that only the central outer ring contacts the road. When the road conditions become rougher, the sidewalls temporarily buckle in response to the increased road forces, simulating a low pressure conventional tire having ample space for deformation.
Although there have been significant developments in the developments of tires with regard to fuel consumption and dynamic road behavior, significant room for improvement remains.